Apparatus for enameling articles



Jan 5, 1937 c. s. LARSON ET AL 2,066,628

APPARATUS FOR ENAMELING ARTICLES Filed Aug. 3, 1935 9 Sheets-Sheet 1 Wal fer A. Kuehler* ATTORNEY.

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Jan. 5, 1937. LARSON ET AL I 2,066,628

APPARATUS FOR ENAMELING ARTICLESA Filed Aug. 3, 1935 9 Sheets-Sheet 5 INVENTOR5: E1. Clas 5. Larson Walzer A .Kuehler HKM@ ATTORNEY.

Jan, 5, 1937.

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Jan. 5, 1937. c. s. LARsoN ET AL APPARATUS FOR ENAMELING ARTICLES Filed Aug. 5, 1935 9 Sheets-Sheet 9 FIG. Z4.

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' the purpose of preventing corrosion from the soil. The application of vitreous enamel to pipe lsec- Patented Jan.

PRATUS FOR ENMELING t Clas S. Larson and Walter A. Kuehler, Milwaukee,

Wis., assignors to A. O. Smith Corporation, Milwaukee, Wis., a. corporation of New York Application August 3, 1935, Serial No. 34,513

4 Claims.

This invention relates to apparatus for enameling articles such as large sections of pipe of the order of iort'y feet or more in length as employed in underground pipe lines for the long distance transmission of oil and gas. Such pipe is preferably covered with a coating of vitreous enamel for one ton; and another results from the size and length of the pipe sections, requiring that the fusing of the enamel be done while the pipe is in. a vertical position rather than horizontal,

since in the latter position it would be difllcult, if not impossible, to support the pipe against-saggixig at the high fusing temperature required without destroying the coating.

The object o! the present invention is to provide an apparatus constituted of a single machine for applying the vitreous enamel coating to an article such as pipe.

Another object is to provide simple and ef cient apparatus for continuously and progressively lperforming the steps required in vitreous enameling sections of pipe and like articles.

Other objects will appearhereinafter.

This application is closely related to the following: application for Enameling machines, Serial No. 628,654, filed by Clas S. Larson on August 13, 1932; patent for Enamel spraying.

booth, No. 2,026,080, granted to Adam Ziska; patent for Pipe handling apparatus, No. 2,010,820; granted to Clas S. Larson; application for Compensators for hoisting apparatus, Serial No. 623,5 178. led by Otto E. Uecker on July 18, 1932; application for Elevator for conveyor trucks, Serial No. 34,511, led by Walter A. Kuehler on August `3, 1935; application for Elevator for conveyor systems, Serial No. 34,512, filed by Clas S.-Larson and Walter A. Kuehler on August 3, 1935; and an application for Conveyor truck, Serial No. 31,988, led by Clas S. Larson on July 18, 1935; all of which are assigned tok a common assignee with the present application.

The preferred embodiment of the present invention is illustrated in the accompanying drawings in which:

Figure 1 is a schematic elevational layout of the machine circuit;

Fig'. 2 is a diagrammatic view of the path of the trucks;

Fig. 3 is a side elevation showing the drive for the several conveyorsand elevators;

Fig. 4 is a top plan view showing the drive as 5 mustrated in the left han of rig. a, l

Fig. 5 is a top plan view complementary to Fig.

tand show/ing the drive as illustrated in the right half of Fig. 3;

Fig. 6 is a longitudinalv section showing the lo conveyor track, a truck and the main chain;

Fig. 7 is a schematic plan View oi@ the machine circuit;

Fig. 8 is a transverse sectional View of apparatus shown in Fig. 6;

16 Fig. 9 is a top plan view of apparatus shown in Fig. 6, parts being broken away;

Fig. l0 is a side elevation illustrating the transfer of a truck from one horizontal conveyor chain to another;

Fig. 11 is a transverse section taken on line II-il of Fig. 10;

Fig. 12 is a transverse section of the apparatus showing an elevator;

Fig. 13 is a longitudinal section of the apparatus 25 and is taken on the line I3-I 3 of Fig. 12; and

Fig. 14 is a section taken on line Ill-i4 of Fig. 12.

The machine in its general outline, as illustrated in Figures 1 and '7, follows the outline of 30 the process for treating the pipein which the enameling mixture is ilrst applied to the surface of the pipe, then it is dried and preheated, and then fused in a furnace at a fusing temperature such as 1550" F., after which the pipe and enamel coating are either cooled slowly, or are quenched in a uid toc'ool the* same rapidly and.give desirable properties thereto as set forth in Patent No. 1,919,136 issued to L. R. Smith on Enameled metal articles and method of producing them.

The pipe section I is first tipped from horizontal position to vertical position by suitable mechanism at 2 and which is set forthV and claimed in detail in Patent No. 2,010,820, above referred to. As the pipe swings to vertical posi- 45"' tion it. becomes attached to a truck 3, to be described later, and which is set forth and claimed in copening application Serial No. 31,988, referred to above. It is then picked up by the first elevator 4 and as it is drawn upwardly for 50 its whole length it passes through the spraying booth 5 and receives a thin coat of enameling material on the outside.

The detail construction of the spraying booth 5 is set forth and claimed in Patent No. 2,026,080 ,l

loading, spraying and referred to above. Upon passing of the pipe through the spray booth 5, the truck 3 from which it is suspended reaches the upper or main conveyor level. The truck and pipe are then moved horizontally through the drying and preheating oven 6 at the end of which it reaches the second elevator 1 which lowers it to the furnace level, the pipe I being lowered through an opening 8 in the top of the furnace 9 while the truck 3 is disposed above the furnace. lThe pipe I is then moved horizontally through" the furnace at a ratewhich will produce the desired fusion of the enamelby the time the pipe reaches the end of the furnace. Two openings are provided in -the furnace at the discharge end; one opening IIJ being in the top and being for removal of the pipe upwardly by elevator I I should it be desired to cool the pipe slowly, the other opening I2 extending in alignment through both top and bottom of the furnace to provide for lowering the section of pipe bodily into a quenching tank I3 beneath the discharge end of the furnace.

Elevator I4 is provided for lowering the pipe from the furnace into the quenching bath and the details of construction of this elevator are more fully set forth and claimed in application Serial No. 34,512 above referred to. During quenching the pipe is moved horizontally in the tank I3 and is then removed upwardly by elevator I5 to the furnace level, but outside of the furnace. It is then'moved horizontally to elevator I6 which moves it upwardly to the upper main conveyor level, the same as it would have been had it been drawn out of the furnace by elevator II, without quenching. In either event, the pipe is then moved horizontally through a slow cooling chamber I1 to elevator I 8 where it is lowered onto an unloading cradle I9 similar to the mechanism 2 and which removes the pipe from truck 3 and swings the pipe to horizontal position Where it is removed from the machine as a finished product.

Fig. 1 shows a side elevation of the machine as though the path of movement of the pipe is from left to right in more or less of a straight line. However, the machine, as built, provides a continuous circuit as illustrated in Fig. 7 where the drying oven and cooling chamber are arrangedv at opposite ends of the conveyor, the unloading are on one side, quenching tank are on the arrangement of circuit may and the furnace and other. Any suitable be provided.

As shown generally in Figs. 1, 3, 4 and 5, the horizontal conveyor system comprises a main conveyor 20 at the top of the structure, a furnace conveyor 2I, a conveyor 22 for moving the -pipe through the quenching tank, a conveyor 23 and an auxiliary conveyor 24 at the end of the furnace for transferring the pipe between elevators, and a transfer conveyor 25 for transferring the empty trucks 3 from the unloading mechanism I9 to the loading mechanism 2. The details of construction of the several conveyors are much alike, and are shown in Figs. 6, 8, 9, 10 and 11.

In the main conveyor circuit 20, the trucks 3 are mounted on a pair of rails 26 which extend throughout the path of movement of the trucks in that circuit. The trucks 3 are propelled along the rails 26 by a continuously moving endless chain 21 which is suspended at short intervals by means of trolleys 28 from a track 29 located above the trucks. Each trolley 28 is provided quenching conveyor 22, the I to conveyor 23 `being arranged vertically so that at its underside with pivoted hooks 30 adapted to engage lugs 3I on the top of a truck 3. 'I'he truck 3 is released from the hook 30, as the former reaches an elevator which is adapted to lower the truck, by means of stationary blocks 32 supported from the main frame of the machine and which are located in the path of the hook 30 so that as the latter engages the block, Y

the hook is raised out of engagement with the lugs 3I. When a truck is raised by an elevator to the level of conveyor 20, the hook 3U automatically engages the lugs 3l as the hook moves slowly over the top of the truck.

For the purpose of raising or lowering the trucks at the elevators, the rails 26 are interrupted at the several elevators and short elevator rails 33 are .provided for supporting the trucks during vertical movement, as will be described in more detail hereinafter in connection with Figs. 12 to 14. It will be noted that the main conveyor 20 is at the top of the machine and that the trucks 3 are not raised to a higher level since the chain 21 prevents am, raising of the trucks. The trucks are moved upwardly to the rails 26 or downwardly therefrom, as may be desired.

The furnace conveyor 2I is constructed dinerently from the main conveyor 20 in that the trucks 3 are lowered onto the conveyor or raised from it. The conveyors 2I, 23 and 24 are arranged end to end in overlapping relation as i1- lustrated in Figs. 1, 3, 10 and 11. A single pair of rails 34 is provided for supporting the truck during horizontal movement along these conveyors. In conveyor 2I instead of one conveyor chain, two endless chains 35 are provided, one on either side of the trucks. The chains are arranged beneath the trucks and are provided with upwardly extending hooks 36 for engaging lugs 31 on the trucks.

As the trucks reach the end of conveyor 2 I, and should it be desired to lower the trucks to the trucks are transferred which moves them onto the elevator I4 for lowering.

The conveyor 23 has a pair of endless chains operating in parallel above the path of the trucks and having downwardly extending hooks 39 for engaging lugs 40 on the trucks. The chains 38 overlap the chains 35 suiliciently to effect engagement of the lugs 40 by hooks 39 prior to the release of the lugs 31 from hooks 36.

- The chains 35 travel on sprockets 4I and the chains 38 travel on sprockets 42, the sprockets the release of lugs 31 is effected by the dropping of chains 35 and hooks 36 over the sprocket 4I and away from the truck 3, and the engagement of lugs 40 by hooks 39 is effected by the lowering of the chain 38 and hooks 39 over sprocket 42 and into the horizontal path of the lugs 40.

'I'he quenching conveyor 22 is constructed slmilar to furnace conveyor 2| and need not be separately described. N

'I'he auxiliary conveyor 24 is also constructed similar to the furnace conveyor'ZI and is adapted to receive a truck from the end of conveyor 23 and transfer the same to the elevator I6 for raising to the main conveyor 20. The raising of the article from the quenching bath to the main conveyor level is taken in two steps, first from the quenching conveyor 22 to the transfer conveyor 23 by elevator I5, and then from the auxiliary transfer conveyor 24 to the main conveyor 20, by elevator Ii.

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' guides 45.

aceaeee After the truck has been lowered by elevator i5 and relieved of its load by mechanism i5, it is transferred by conveyor 25 to the elevator 5 where it is loaded with another pipe section and starts through the circuit again.

The general construction of elevator t is shown in Figs. 12 to 14. The other elevators are similar in construction. The elevator shown is the same at that set forth and claimed in application Serial No. 34,511, above referred to. Various embodiments might be employed. For instance, the elevator set forth and claimed in application Serial No. 623,654, above referred to, might be used. As preferred, the elevator has a carriage 44 supporting the short rail sections 33, and adapted to be raised orlowered in vertical The vertical 'movement of the carriage is effected by two pairs of endless chains 46 operating on opposite sides of the carriage and each pair having a crosshead 41 connected to support the carriage. The chains 46 pass over and are driven by sprocket wheels 48 at the top of the elevator shaft, and pass under sprocket wheels or shoes 49 at the bottom of the shaft. As the chains 46 travel in synchronism the crosshead 41 secured to the chains on opposite sides of the carriage 44 moves up and down, thus effecting vertical movement of the carriage 44 and rail section 33.

As illustrated in Figs. 3, 4, and 5, the several parts of the machine are all driven from a single source of power mechanically connected to each part. In this way all parts of the machine are kept in synchronism, it.belng impossible for any part tp get out of step with the others.

The loading mechanism 2 and unloading mechanism I9, however, are driven by separate motors 50 and 5l, respectively, each of which is controlled by limit switches in circuit with a synchronizing switch 52 operated by the transfer conveyor 25, as illustrated in detail in Patent No. 2,010,820, above referred to.

The main drive motor 53 for the machine is located at the top and is connected by suitable speed reducing gearing 5t to the main drive shaft 55 which extends for nearly the fulllength of themachine. A small motor 55 is preferably provided to'operate the machine at slow speed for adjusting and is connected to 4the main motor shaft by the speed reducer 5l and a clutch 55, see Fig. 4. A brake 55 is provided for the motor 55 to effect rapid stopping of the same.

At one end of the shaft 55 it is connected through a suitable speed reducer 55 and gearing 5i to a large horizontal sprocket wheel 52 which drivesthe main conveyeiechain 31h The sprocket wheel 52 is at one end of the circuit of chain 2l and determines the path of the chain at that end. At the other end of the circuit, the chain 2li passes around a shoe 55 which is adjustable to effect tightening or loosening of the chain.

The elevator t is driven directly from main shaft 55 through the bevel gears 55, horizontal shaft 55, bevel gears '55 at each end of the shaft.

55, vertical shafts 5l, and gears 55 whichgdrive the upper sprocket wheels 55. Elevators l, lll, it, i5, iii and i5. are similarly driven from bevel gears 59, T10, 'iii l2, i5 and lil, respectively, on the main drive shaft 55. Elevator ii has a clutch 'i5 provided in its drive for the purpose of disconnecting the elevator when it is desired to use elevators it, l5 and i6. A clutch l5 is provided in main shaft 55 for disconnecting the left end of the shaft and prevent operation of elevators it, i5 and, i5 when it is desired to use elevator il.'

Elevator" it, which lowers the pipefrornthe furnaceinto the quenching bathhas a special safety feature which permits continued lowering of the pipe so as to get the truck 3 out of the hot furnace should the machine stop for any reason midway in the lowering of a pipe section. As shown, a clutch il is provided in the drive for the elevator I4 similar to clutch 'l5 for elevator .Ill for the purpose of disconnecting elevator it from the drive. A brake 'I8 is provided on the elevator, I4 to permit lowering4 of the elevator slowly as desired.

The furnace conveyor 2l is driven from the gear box 19 on the main shaft 55, through the horizontal shaft 80, bevel gears 8|, vertical shafts 82 and gears 83 which are connected to drive the sprocket wheels 4I at one endof the conveyor.

The conveyors 22, 23 and 24 are driven from the gear box 84 through vertical shaft 85 and suitable connections therefrom to the sprocket wheels of the respective conveyor chains.

The conveyor 25 is driven from gear box 86 on the main drive shaft 55, through the horizontal shaft 81, bevel gears 88, vertical shaft 89 and gears 90 connected to drive the sprocket wheels for the conveyor chains.

By providing a single complete drive by which all parts are operated in synchronism and in continuous movement, a very efficient enameling operation is obtained, since each successive article will be treated exactly alike and there will be but slight-variatiomif any, in quality of the nnished product.

The invention may have various embodiments within the scope of the accompanying claims.

We claim:

1. In a, machine of the class described, a pair of horizontal rails defining a conveyor path, means to lower a truck onto said rails for movement therealong, an endless chain or the like disposed parallel to said rails and beneath said truck having means thereon for engaging said truck and moving the same along said rails, said chain passing downwardly to a return circuit to release said truck prior to reaching the end of said rails, a second endless chain disposed above said truck and adapted to engage the same and continue its movement on said rails as said first named chain releases said truck, and means disposed in the path of said truck as it is propelled forwardly by said second named chain for lowering said truck from saidconveyor path, rails and chain.

2. In a machine of the class described, a pair of horizontal rails defining a conveyor path, means to raise a truck to the level of said rails for movement therealong, an endless chain disposed above said truck and extending'pa'rallel to said rails, means on said chain for engaging said truck to move the same onto and along said rails, a, second endless chain disposed beneath the path of said truck and having means to engage the truck and to continue its movement forward on said rails as the truck is released from said first named chain, and means disposed at the end of the path of the first mentioned chain for elevating the truck from the level of said rails.

3. In a machine of the class described, a pair of horizontal rails defining a conveyor path, means to lower a truck onto said rails for movement therealong, an endless chain or the like i disposed parallel to said rails and beneath said truck vhaving means thereon for engaging said truck and moving the same along said rails, said chain passing downwardly to a return circuit to 75 release said truck prior to reaching the end of said rails, a second endless chain disposed above said truck and adapted to engage the same and continue its movement on said rails as said first named chain releases said truck, means disposed in the path of said truck as it is propelled forwardly by said second named chain for lowering said truck from said conveyor path, rails and chain, and means for driving said chains and last named means in timed relation to eiect the continuous movement of the truck.

4. In a machine of the class described, a pair of horizontal rails defining 'a conveyor path, means to raise a truck to the level of said rails for 15 movement therealong, an endless chain disposed above said truck and extending parallel to said rails, means on said chain for engaging said truck to move the same onto and along said rails, a second endless chain disposed beneath the path of said truck and having means to engage tpe truck and to continue its movement forward on said rails as the truck is released from said rst named chain, means disposed at the end of the path of the rst mentioned chain for elevating the truck from the level of said rails, and means for driving said chains and last named means in timed relation to effect the continuous movement of the truck.

CLAS S. LARSON.

WALTER A. KUEBLER. 

